A research of the epidemiology of enterohaemorragic E.coli O157 in wild rodents

野生啮齿动物肠出血性大肠杆菌O157的流行病学研究

• 批准号: 10660298
• 负责人: SUGIYAMA Yoshihiro
• 金额: $ 2.18万
• 依托单位: RIKEN INSTITUTE (1999-2000)University of Tsukuba (1998)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660298/
• 关键词: enterohaemorragic Escherichia coli; wild rodents; epidemiology; 病原性大腸菌; 環境; O157; 野鼠; 疫学

To survey the epidemiology of enterohaemorragic Escherichia coli, (E.coli) wild rodents, river water and soils were collected. Verotoxin producing E.coli were isolated from 3 of 211 wild rodents (1.4%) captured in a mountainous area and 1 of 62 (1.6%) in the place of relating domestic animals. Serotype O157 E.coli, which was typical enterohaemorragic E.coli (EHEC) serotype, was isolated form wild rodents, but it was decided as non-pathogenic E.coli. Four pathogenic isolates were identified the production of Vero toxin 1 (VT1) by the toxin detection kit and PCR, but it could not be done in O-serotype. And, I examine an effective method to isolate EHEC from a sample of soil and river water, but it was not possible to isolate EHEC from these environment factors. While EHEC were experimentally inoculated into some kinds of soils and examined the existence period in these soils at different temperature. Extinction of EHEC was early in a condition of 37℃ and it became hardly to detect the organisms at 3 months after inoculation. But, at 23℃ the number of bacteria is kept the considerable amounts in soils. However a high number was maintained in the soil during approximately 1 month independently of temperature condition. It was suggested that the feces from EHEC infecting cattle fall to the ground, the ground soil is polluted by EHEC and that pollution will be continued between several months. Furthermore, I examined to detect the Vero toxin antibody at 252 serum samples from wild rodents. Three samples were reacted to VT 1 only and 4 samples were reacted to VT1 and VT2. But there is no sample to react to VT2 only. Total at 7 samples (2.8%) the antibody to Vero toxin was detected. And, 5 samples (2.0%) showed O-agglutination to O157 at the serum dilution 80 times. In this study, EHEC O 157 : H7 was not isolated from wild rodents, but it suggested that there is high possibility of possession of EHEC O157 at wild rodents.

为调查肠出血性大肠杆菌的流行病学，采集了野鼠、河水和土壤样品。从山区捕获的211只野生啮齿动物中分离出3只（1.4%）产Vero毒素大肠杆菌，从62只相关家畜中分离出1只（1.6%）产Vero毒素大肠杆菌。O 157型大肠杆菌是从野生啮齿类动物中分离到的典型肠出血性大肠杆菌（EHEC）血清型，经鉴定为非致病性大肠杆菌。用毒素检测试剂盒和PCR方法对4株致病菌进行了鉴定，均为Vero毒素1（VT 1）的产生菌，但对O血清型的致病菌均未进行VT 1的检测。而且，我研究了一种有效的方法，从土壤和河水样品中分离出EHEC，但不可能从这些环境因素中分离出EHEC。同时，将肠出血性大肠杆菌接种于几种土壤中，研究了不同温度下肠出血性大肠杆菌在土壤中的存活期。在37℃条件下，肠出血性大肠杆菌消亡早，接种后3个月已几乎检测不到。但在23℃时，土壤中的细菌数量仍保持相当数量.然而，在大约1个月的时间里，土壤中的数量很高，与温度条件无关。结果表明，EHEC感染牛的粪便落到地面，地面土壤受到EHEC的污染，污染将持续数月。并对252份野生啮齿动物血清进行了Vero毒素抗体检测。3份样品仅与VT 1反应，4份样品与VT 1和VT 2反应。但是没有样品仅与VT 2反应。共检测到7份（2.8%）Vero毒素抗体。在血清稀释80倍时，有5份（2.0%）样品显示O-凝集反应。本研究未从野生啮齿动物中分离到EHEC O 157：H7，但提示野生啮齿动物中存在EHEC O 157的可能性很大。